Can be used as a shield, this old American documentation circuit offers digitally selected attenuation values from 1 to 0.0001. The component used is uncommon today.
This circuit indicates whether the voltage to be measured is higher or lower than the zener diode...
Obtained from an English publication, this circuit actually needs a current limiting resistor,...
Constant current sources are used in applications such as battery chargers, electrolytic tanks, etc....